Flow divider device



Oct- 6, 1953 c. H. sTocKDALE E-rAn.

FLOW DIVIDER DEVICE 2 sheets-sheet 1 Filed March 2l, 1950 $2.2.: wvo-m 2.35... 95.4 3:25 28m e sw m m N mi m O m H- m 4 1 NSM. Y R n E O O W w w VH J T u .m x N T a mm \m w l A x l. a M AM- EI 4. m m. D v Ehm 5MM-wo 4V, ..1 mm, D m m mm km 9v QE dEPr ..0 `W EW .Boum 322 m\ a ,d ci des. QN Ev-.E mSoI o Oct. 6, 1953 c. H. sTocKDALE ETA'. 2,654,384

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Patented Oct. 6, 1953 UNITED srArEs eA-r or FICE FLOWr DIYIDER DEVICE Gnarles` H; Stockdale, Springield, and. Douglas Johnson.. Ridley Bark, Pa., assignors to. West@` inghouse Electricl Qorporati'onast. Pittsburgh. Pa., a corporation of Pennsylvania ApplicationiMarch. 21, 1950, Serial No. 150,966

' 5.. Claims.. 1..

This inventionA relates; to fuel supply-systems andi more` particuIarlyA to.y fuel.; supply apparatus;

fora-gas turbine power plant',

' -Inthe operation of a; gas. turbine power pla-nt .utilizing Huid fuel', it is desirable. to eiject divi.- sion. off the flowv of fuel in substantially equal amounts. Ito. the respective fuel nozzles; of the combustion apparatus, in order that; there may be-y uniform heat release and consequentlyA uni.- fo-rm temperatureV distribution at all circumferential points ofthe turbine inletpassage. With an. aviation :turbojet engine, operative at altitudes above 405000 feet, equalized division of fuel ow is particularlyl desirable for preventing disturbances of combustion stability under the` conditions of vaporization, effusion of air and heat eifect encountered at suc-h altitudes. One object of; the present invention is the provision of improvedl flow divider means for achieving the foregoing desired results.

It vhas been proposed to equip a gas turbine yengine with pressure responsive nozzles having variable Qrices, which are individually supplied with fuel from a pluralityv of balancing valves fed from a now divider device havinga, correspending number ofv orifices of predetermined flow area. In the ovv divider device to which fuel. is, metered from the usual pump andi control apparat-us, the fuel pressure on the up- Stream Sido of `each. orince. is the same. The functipllA of the balance, valves is to maintain substantially. equal fuel pressures on the down- Stream, Sides of `the` orices thereby to effect equal pressure drops thereon for. `I,uomoting uni'.- form flow. through all. orifices. U11-dcr Service conditions.. honorer, ity may be. dilcult to achieve exact4 equalization, of, ilow. with. such. a flow divider device,` due to the difficulty f.. D110: vidina identical orifices 'to' ensure. equal. fuel ovv rates for all nozzles. Another objectv of this in ventionis to. provide auxiliarymeans, adapted for.- cooperation with aifuel system of the, BfQre.- said tvp@r for obviating any difficulty heretofore eigeerienced` with respect, to variations inv Qlue ow areas.

The. problem of; fuel flow diison iS.. 1Gillet/.mah A flow divider; operative with all; accuracy 0f i517@ may, for miam-plc,- nerrmt. turbine inlet circumferential temperature variationsjY on selected radius, rangingfroml 65.0 F.A to,250,"f Ef. on various engines. In the accompanying draws ings, hereinafter more fully described; Eig. 2 constitutes a chart shovvingfa typicalv turbine inlet temperature pattern. Curve A shows. the

coldest. radial. temperatureplot. occur/ring. at, a selected circumferential location., Curve C showsthe hottest radial, temperature plot. occurringl at, another circumferential location.. Curve B represents.v the average of all radial tempera.- turo plots taker-1- from all circumferential areas of 'the turbine inlet. The amount. of energy re.-l leased Within the engine is represented 'by the area. undery curve 13 Since; point. X indicates. the maximum. tempelailulieallowable upstream of the turbine, it Will be seen that. fuel caniche sup,- .pliedto the engine in ever increasing quantities only until some area in the turbine inlet reaches the` point` of about. v18062- -Which limi-ts the performance of tno.; engines Eurthen increase in rate of fuel Elow would reduce the l'ie` of the tunbine and endanger=the.engi.1:1.c.=-

If the maximum turbine inlet. circumferential temperature variation on any'r given` radius could be reduced to zero. degrees 605i F1), their the curves A, B and Ci of the chart would coincido, andI curve C would: not: only bethe hottest radial temperature plot, but: the coldest. the average radialy temperature plot as Well', so; that the amount of energy released Within the engine would be that representedl by the area under curve C; It is another object of:V the present: invent-ion to provide improved flow: divider appa.- ratuspromoting the attainment ofthe above ideal .performance characteristics, by effecting equalization of the fuel flow through a plurality of nozzles witha degree ofY` accuracy rendering possible the achievement of a favorable uni'- formity of temperature circumferentiall-yof the turbine inlet..

Since the. safe available thrust of a turbojet engine thus approaches a maximum when its turbine. inlet cirournicrcrltall temperature variation is zero, many existing types of turbojet .could safely Ibe. operated to develop more thrust if equipped with` means for. reducing Variations turbine inlet. circumferential teroneratulc- A further object of ther invention is to, provide HOW divider means which is adapted for association with combustion,- apparatus. of the grouped unit or `can type, aswell as.. with annular combustion apparatus, and. which is 'thus4 readily. applicable to` existing power, .plants `for increasing the thrust rating thereof.

A feature os the invention. is the. provision of a flow; dividerdevice forr association, with aplu.- rality of fuel` nozzles,J comprising afstationary member having.- an equal Vnumber of circumferential'ly spaced fuclppasags, and: a; -lta-PY orifice plate having orices of predetermined flow area cooperative therewith to effect flow of fuel =to each nozzle by Way of all such yorifices in succession, thus effectively distributing the same average quantity of fuel to all nozzles within a short interval of time.

These and other objects are eifected by our invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. l is a schematic elevational view, partly in section, of an aviation gas turbine power plant equipped with fuel flow distribution apparatus constructed in accordance with the invention;

Fig. 2 is the temperature distribution chart already referred to;

Fig. 3 is a diagrammatic enlarged-detail View of improved fuel distributing apparatus constructed in accordance with the invention and adapted for association with the power plant as shown in Fig. 1;

Fig. 4 is a fragmentary plan view, partly broken away, of the stationary and rotary orice plates of the flow divider device shown in Fig. 3; and

Fig. 5 is a sectional development of a portion of the orifice plates taken along the line V-V of Fig. 4.

Y In Fig. l of the drawings, the invention is illustrated in association with the combustion apparatus of a conventional gas turbine engine 9, which in the form shown comprises a cylindrical outer casing structure I having mounted therein a sectional core structure I I, which with the casing structure I0 denes an annular flow passageway I2 that extends longitudinally through the engine from a frontal air intake opening I3 to a rearwardly-disposed discharge nozzle I4. The casing structure I0 is adapted to be mounted in or on the fuselage or wing of an aircraft (not shown), with the intake opening I3 pointed in the direction of night. The axially-aligned operating elements of the engine disposed in the casing structure I0 include an axial flow compressor I having a rotor I6, annular fuel combustion apparatus I1, and a turbine I8, the rotor I9 of which is operatively connected to the compressor Vrotor I6 through the medium of ahollow shaft '20, which may be suitably journaled in the casing structure. In operation, air drawn into the intake opening I3 is compressed by the compressor l5 and delivered to the combustion apparatus I1, to which fuel is supplied by way of apparatus hereinafter described. The resultant hot motive gas is then supplied from the combustion apparatus to the turbine I8, and is finally discharged through the nozzle I4 in the form of a jet establishing-a propulsive thrust.

According to the invention, the fuel supply system may comprise a reservoir 20, fuel governor and pump apparatus 2I of any desired type for supplying fuel at a rate selected according to the setting of a throttle 2Ia, a flow divider or distrbuting valve device 22, and a plurality of pressure balancing valves or equalizing valve devices 23. The driven elements of the governor and pump` apparatus 2l are operatively connected to the rotor of the engine 9 through the medium of suitable gearing (not shown) in a gear box 25,

which is carried on the outer casing I0.

The equalizing valve devices 23 are individually operative to supply fuel to the required number of yfuel nozzles 24 which are circumferentially spaced with relation to the annular combustionv apparatus I1. 'Ihese nozzles are preferably-of 4 the variable orifice type, and may each have the construction of that illustrated in section in Fig. 3, comprising a casing having a bore 26 in which a piston valve 21 is slidably mounted. The piston valve 21 is subject to the opposing pressures of a spring 28 and of fuel admitted to the bore 26 by way of an inlet passage 29, and is operative to uncover one or more ports 30, according to the fuel pressure, for eifecting discharge of fuel from the bore through an outlet opening 3 I.

Referring to Fig. 3 of the drawings, the ow divider or distributing valve device 22 comprises casing sections 32 and 33 having a fuel receiving chamber 34, which communicates through an inlet conduit 35 with the discharge side of the governor and pump device 2| shown in Fig. 1. Mounted in the casing section 33 at the end of the chamber 34 opposite the inlet thereof is a stationary fuel collector plate 36 in which are formed a plurality of circumferentially disposed outlet ports 31 corresponding in number to the nozzles 24. In a typical installation, sixteen nozzles and the same number of ports 31 will be provided. The respective ports 31 are somewhat enlarged adjacent the inner surface of the collector plate 35, and are separated by radial ridges or knife edges 3S formed on the inner surface of the plate, as best shown in Fig. 5. For effecting supply of fuel to all the ports 31 in succession, there is provided a rotary orice plate or valve member 4U, which is rotatably mounted in the casing section 33 adjacent the plate, Vand has circumferentially spaced calibrated orices 4I corresponding in number to the ports 31 and adapted to register successively therewith during rotation of the orifice plate. All orifices 4I are made as nearly identical as possible, and may be formed in plugs lila screwed into suitable openings formed in the orifice plate 40. The valve member 40 has an axial shaft 42 which is journaled in bearings 42a carried by the casing section 32. The shaft 42 extends through the chamber 34, the outer end of the shaft being connected to the splined end of a rotary cable 45 operative for turning the shaft. The cable 45 is housed in a flexible tube 46, and terminates in a suitable coupling (not shown) in the gear box 25, which contains a driving train of Yreduction gears operative to drive the cable and rotary plate 36 from the engine 9.

Mounted adjacent the distributing valve device 22 is a control valve or reducing valve device 5I, comprising a valve element 52 which is disposed in a valve chamber 53 communicating through a conduit 54 with the inlet 29 of one of the nozzles 24. A spring 56 is interposed between a plug 51 and the valve element 52 for urging the latter toward a seat 58 to control'communication between the valve chamber 53 and a passage 59 leading from one of the ports 31 of the distributing valve device 22.

Each of the similar equalizing valve devices 23 associated with the individual nozzles 24 cornprises casingV sections 62 and 63 between which is clamped a diaphragm 64, the casing sections and diaphragm cooperating to provide, on one side of the diaphragm, a valve chamber commlmicating through a conduitand passage 65 with one of the ports 31 in the distributing valveV device 22. Formed at the other side of the diaphragm 64 is a chamber 61 which isY connected toa control conduit 68; The control conduit 68 communicates with the passage 59 ofthe control valve device 5I. Mountedin a guide 10'in'each valve chamber 65 Vis 'a slide valve 1I, which `is operativelyv connected -to 'thedia-phragm 64 and has an annular r groove A12. for controllingcommunicat'ionf'between the valve chamber `65 and a port and conduit 13 communicating `with the inlet 29 of'the associa-ted nozzle 24. The equalizinfg' valve devices 23 and reducing valve .device 5l-correspondgenerally to the similar appara-tus disclosed in the application of Cyrus F. Wood-and LinnrFJCummings filedvJune 10, 1949, Serial No.

98,334, and assigned to the assignee of the presi ent application.

The apparatus shown in Fig. '3' opera-tes as follows: fuel runder pressure deliveredzhy the governor and pump equipment 2|,is suppliedby way o f ythe conduit 35 to the chamber 34 of the ydistributing valve device 2 2, and thence flows through the vregistering orifices and .ports 4| and 31 .and related conduits 6'6` to the valve chambers 65- of the several equalizing valve devices 23. .At the same time, the valve---element152 is operated by fuel under pressure flowing through the passage 59 to meter some of the fuel through conduit 54 to the corresponding nozzle 24, While the back pressure of fuel in passage 59 constitutes a control pressure and is communicated by way of the control conduit 68 to the diaphragm chamber S1 of each equalizing valve device 23. The diaphragms 64 of all equalizing valve devices 23 are thus subjected to the same control pressure for rendering uniform the rate of flow of fuel by way of the associated slide valves 1| to the respective nozzles 24.

With the orifice plate 36 rotated by means of the cable 45, the fuel is fed from the chamber 34 to the ports 31 through all of the orifices 4l in succession. Although the orices 4l are intermittently brought into and out of registration With the respective ports 31, fuel is thus supplied through the plurality of conduits 66 to the connected equalizing valves 23 and nozzles 24 in successive increments ata sufficiently rapid rate to produce, in effect, a continuous flow of fuel to each area of the combustion apparatus of the engine. The distributing valve device 22 is thus designed to divide the flow of fuel into the desired number of substantially equal paths, irrespective of minor variations which may be unavoidable in formation of the flow areas of the orifices. The quantity of fuel fiowing through each orifice 4I is thus successively injected through all of the ports 31, and is ultimately fed to all of the fuel nozzles in turn, so that each nozzle will pass the same average amount of fuel over an interval of time. If it is assumed that a speed of R. P. M. is adapted for the rotating orifice plate 40, for example, fuel flowing through each of the orifices 4I will be injected into the combustion chamber by Way of a corresponding nozzle during an interval of 1/160 minute at a time. Each orifice thus supplies each nozzle during very short intervals of time, and all orifices supply all nozzles with the result that appreciable variations in turbine inlet circumferential temperature will be minimized.

It will be seen from the foregoing that the improved flow divider apparatus will thus be operative to ensure equal distribution of fuel flow to the fuel nozzles 24 so as to facilitate maintenance of ow balance and consistency of fuel distribution in the gas turbine engine 9. With temperature variations at the turbine inlet reduced to a minimum, the thrust of the engine nozzle I4 may safely be increased, without endangering the turbine blades, and without increasing the likelihood of cracking of the usual 6,. turbine inlet nozzle structure due to thermal shock.

While -we have shown our invention -in ibut one form, it will'be obvious to those skilled-in-.thcart that it is not so limited,jbut 'is susceptibleof variouschanges and modications without departing from the-spirit thereof.

What is claimed is: f

l. Fuel flow .divider means for. a gas; turbine engine having annular combustionapparatus and a` plurality. of zcircumferentially spaced'fuel .supply .devices therefor, .comprising casing structure forming ya .chamber 'having an. inlet communicate ing with a source of fuel under pressure, .said casing structure including Aa vcollector .plate form-- ing a wall of said chamber and'having aplurality ofcircumferentially `spaced discharge ports each adaptedf to communicate with one of 'said'fuel supply devices, saidA collector plate having knife edges formed between and separating saidporlts on the side adjacent said chamber, a rotary orifice elem-ent -mounted in said chamber adjacent the side of the collectorrplate having said knifeedges between said discharge ports and having a plu-` rality of similarly spaced restricted orifices successively registerable therewith, and means for driving said orifice element from the engine for effecting flow in separate courses from said chamber through said ports to said fuel supply devices by way of all of said restricted orifices in rapid succession.

2. Fuel supply apparatus for effecting equal flows of fuel under pressure in aA plurality of courses, comprising a source of fuel under pressure, a flow divider device having a chamber communicating with said source, a wall of said chamber having a plurality of circumferentially arranged and uniformly spaced ports, rotary means in said chamber having an equal number of similarly disposed orifices adapted for registering with said ports, said rotary means being operable to bring said orifices and ports rapidly and successively into registration to effect a substantially continuous fluid flow from said chamber by Way of each of said ports through said orifices in succession for effecting equal distribution of fuel delivered from said source, means for establishing a control fluid pressure, and a plurality of equalizing valve devices subject to the opposing pressures of said control fluid and of the fuel flowing through said ports, respectively, for controlling the supply of fuel in equal courses.

3. In a fuel system including a source of fuel under pressure, in combination, means including a reducing valve responsive to pressure of fuel from said source for maintaining a predetermined control fluid pressure, a plurality of equalizing valve devices for controlling now of fuel in separate courses from said source in accordance with said control pressure, and a flo-w divider device for effecting uniform distribution of fuel thereto from a common source, said flow divider device comprising a fuel chamber having an inlet communicating with the fuel source, a stationary element in said chamber having a plurality of circumferentially disposed and uniformly spaced outlets communicating with the respective equalizing valve devices, a rotary element mounted in said chamber and having a like member of similarly disposed orifices adapted for registering with said outlets, and means for driving said rotary element to bring said orifices rapidly and successively into registration with said outlets to effect substantially continuous supply of fuel from said chamber through all of said orifices in succession to each of said outlets and consequently in separate courses of equal flow rate.

4. A iiowV divider device for distributing fuel from a source of fuel under pressure in a plurality of discharge courses comprising a casing having `a fuel receiving chamber communicating with said source, an element disposed in said chamber and having a plurality of circumferentially arranged and uniformly spaced ports corresponding to saiddischarge courses, respectively, another element rotatably mounted in said charnber and having an equal number of similarly arranged calibrated ports each adapted for registering with the first-named ports, the last named element being continuously rotatable to effect rapid and successive registration between all ports in the respective elements for thereby causing'substantially continuous distribution of fuel from said chamber in uniform discharge courses, and an operating member for said rotatable element.

5, Apparatus as set forth in claim 4 characterized by the disposition of substantially radial knife edges between the ports in at least one of said elements,l with the other element mounted adjacent said knife edges for facilitating substan-` tially continuous flow of fuel from eachof the calibrated ports of the one element to the portsv of the other element as communication thereto is rapidly and successively established during rota' tion of the element driven by the operating member.

CHARLES H. STOCKDALE.Y

DOUGLAS JOHNSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name DateY 1,958,390 Hamilton July 31, 1934 2,145,640 Alden Jan. 31, 1939 2,430,264 Wiegand et al Nov. 4, 1947 2,536,440 Greenland Jan. 2, 195

FOREIGN PATENTS Number Country Date 577,132 Great Britain May 7, 1946 France Apr. 22, 1940 

